Hello, Dahl? What led the 49ers to former Rams safety

With 14 picks in April’s draft, including at least five in the first three rounds, the 49ers will surely target one of the top safety prospects. In fact, a source told The Chronicle this week the Niners have “spent plenty of time doing background” on LSU safety Eric Reid.

Reid, a likely second-round pick, is part of deep safety class that’s headlined by Vaccaro (Texas) and includes Elam (Florida) and Cyprien (Florida International).

The glut of talented safeties – and the 49ers’ bottomless well of picks – helps explain the signing of Dahl, 27, a five-year veteran the Rams didn’t make much of an effort to re-sign after his four seasons in St. Louis.

“(The Rams) had open doors,” Dahl said. “Obviously they felt they needed improvement. … We were in negotiations, but ultimately I came down here, and I felt the love.”

A question asked by 49ers’ fans (at least on social media): Why the love for Dahl, a former undrafted free agent from North Dakota State who isn’t known for his play-making ability (12 passes defended and four INTs in 70 career games)?

Here’s a few thoughts on what likely led the 49ers to Dahl:

** He came cheap. As first reported by the Sacramento Bee, Dahl signed a three-year, $5 million contract. That helps keep the 49ers’ options open. My assumption is they’re done signing free-agent safeties, but Dahl’s modest contract could allow them to remain players in the market.

** He provides much-needed depth at the position. Last year, the 49ers rolled the dice with a group of inexperience/unproven backups behind Donte Whitner and Dashon Goldson, who both made all 19 starts (including playoffs). Their backups – C.J. Spillman, Darcel McBath and rookie Trenton Robinson – have combined for one NFL start. A highly drafted rookie could benefit from the experience of Whitner and Dahl, who has has 42 career starts.

** They obviously see something they like. It’s not like Dahl is a mystery after spending the past four seasons in the NFC West. During the Jim Harbaugh Administration, Dahl started three games against the 49ers. He had 21 tackles and a forced fumble. He’s also had 38 special-teams tackles the past four seasons and Harbaugh is big on versatility.

** Dahl knows the deal. Yes, he started 16 games last year and missed just 41 snaps, but he’s aware that nothing – from a starting gig to a roster spot – is guaranteed in 2013.

“Whether I’m lined up out there from day one, it’s always going to be a competition to keep your job once you’re the starter,” he said. “I’m grateful for the opportunity I was given, and I hope to be that guy.”